Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | #ifndef _LINUX_ELEVATOR_H |
2 | #define _LINUX_ELEVATOR_H | |
3 | ||
4 | typedef int (elevator_merge_fn) (request_queue_t *, struct request **, | |
5 | struct bio *); | |
6 | ||
7 | typedef void (elevator_merge_req_fn) (request_queue_t *, struct request *, struct request *); | |
8 | ||
9 | typedef void (elevator_merged_fn) (request_queue_t *, struct request *); | |
10 | ||
8922e16c | 11 | typedef int (elevator_dispatch_fn) (request_queue_t *, int); |
1da177e4 | 12 | |
8922e16c | 13 | typedef void (elevator_add_req_fn) (request_queue_t *, struct request *); |
1da177e4 | 14 | typedef int (elevator_queue_empty_fn) (request_queue_t *); |
1da177e4 LT |
15 | typedef struct request *(elevator_request_list_fn) (request_queue_t *, struct request *); |
16 | typedef void (elevator_completed_req_fn) (request_queue_t *, struct request *); | |
22e2c507 | 17 | typedef int (elevator_may_queue_fn) (request_queue_t *, int, struct bio *); |
1da177e4 | 18 | |
8267e268 | 19 | typedef int (elevator_set_req_fn) (request_queue_t *, struct request *, struct bio *, gfp_t); |
1da177e4 | 20 | typedef void (elevator_put_req_fn) (request_queue_t *, struct request *); |
8922e16c | 21 | typedef void (elevator_activate_req_fn) (request_queue_t *, struct request *); |
1da177e4 LT |
22 | typedef void (elevator_deactivate_req_fn) (request_queue_t *, struct request *); |
23 | ||
bc1c1169 | 24 | typedef void *(elevator_init_fn) (request_queue_t *, elevator_t *); |
1da177e4 LT |
25 | typedef void (elevator_exit_fn) (elevator_t *); |
26 | ||
27 | struct elevator_ops | |
28 | { | |
29 | elevator_merge_fn *elevator_merge_fn; | |
30 | elevator_merged_fn *elevator_merged_fn; | |
31 | elevator_merge_req_fn *elevator_merge_req_fn; | |
32 | ||
8922e16c | 33 | elevator_dispatch_fn *elevator_dispatch_fn; |
1da177e4 | 34 | elevator_add_req_fn *elevator_add_req_fn; |
8922e16c | 35 | elevator_activate_req_fn *elevator_activate_req_fn; |
1da177e4 LT |
36 | elevator_deactivate_req_fn *elevator_deactivate_req_fn; |
37 | ||
38 | elevator_queue_empty_fn *elevator_queue_empty_fn; | |
39 | elevator_completed_req_fn *elevator_completed_req_fn; | |
40 | ||
41 | elevator_request_list_fn *elevator_former_req_fn; | |
42 | elevator_request_list_fn *elevator_latter_req_fn; | |
43 | ||
44 | elevator_set_req_fn *elevator_set_req_fn; | |
45 | elevator_put_req_fn *elevator_put_req_fn; | |
46 | ||
47 | elevator_may_queue_fn *elevator_may_queue_fn; | |
48 | ||
49 | elevator_init_fn *elevator_init_fn; | |
50 | elevator_exit_fn *elevator_exit_fn; | |
e17a9489 | 51 | void (*trim)(struct io_context *); |
1da177e4 LT |
52 | }; |
53 | ||
54 | #define ELV_NAME_MAX (16) | |
55 | ||
e572ec7e AV |
56 | struct elv_fs_entry { |
57 | struct attribute attr; | |
58 | ssize_t (*show)(elevator_t *, char *); | |
59 | ssize_t (*store)(elevator_t *, const char *, size_t); | |
60 | }; | |
61 | ||
1da177e4 LT |
62 | /* |
63 | * identifies an elevator type, such as AS or deadline | |
64 | */ | |
65 | struct elevator_type | |
66 | { | |
67 | struct list_head list; | |
68 | struct elevator_ops ops; | |
69 | struct elevator_type *elevator_type; | |
e572ec7e | 70 | struct elv_fs_entry *elevator_attrs; |
1da177e4 LT |
71 | char elevator_name[ELV_NAME_MAX]; |
72 | struct module *elevator_owner; | |
73 | }; | |
74 | ||
75 | /* | |
54069588 | 76 | * each queue has an elevator_queue associated with it |
1da177e4 LT |
77 | */ |
78 | struct elevator_queue | |
79 | { | |
80 | struct elevator_ops *ops; | |
81 | void *elevator_data; | |
82 | struct kobject kobj; | |
83 | struct elevator_type *elevator_type; | |
3d1ab40f | 84 | struct mutex sysfs_lock; |
1da177e4 LT |
85 | }; |
86 | ||
87 | /* | |
88 | * block elevator interface | |
89 | */ | |
1b47f531 | 90 | extern void elv_dispatch_sort(request_queue_t *, struct request *); |
1da177e4 LT |
91 | extern void elv_add_request(request_queue_t *, struct request *, int, int); |
92 | extern void __elv_add_request(request_queue_t *, struct request *, int, int); | |
30e9656c | 93 | extern void elv_insert(request_queue_t *, struct request *, int); |
1da177e4 LT |
94 | extern int elv_merge(request_queue_t *, struct request **, struct bio *); |
95 | extern void elv_merge_requests(request_queue_t *, struct request *, | |
96 | struct request *); | |
97 | extern void elv_merged_request(request_queue_t *, struct request *); | |
8922e16c | 98 | extern void elv_dequeue_request(request_queue_t *, struct request *); |
1da177e4 | 99 | extern void elv_requeue_request(request_queue_t *, struct request *); |
1da177e4 LT |
100 | extern int elv_queue_empty(request_queue_t *); |
101 | extern struct request *elv_next_request(struct request_queue *q); | |
102 | extern struct request *elv_former_request(request_queue_t *, struct request *); | |
103 | extern struct request *elv_latter_request(request_queue_t *, struct request *); | |
104 | extern int elv_register_queue(request_queue_t *q); | |
105 | extern void elv_unregister_queue(request_queue_t *q); | |
22e2c507 | 106 | extern int elv_may_queue(request_queue_t *, int, struct bio *); |
1da177e4 | 107 | extern void elv_completed_request(request_queue_t *, struct request *); |
8267e268 | 108 | extern int elv_set_request(request_queue_t *, struct request *, struct bio *, gfp_t); |
1da177e4 LT |
109 | extern void elv_put_request(request_queue_t *, struct request *); |
110 | ||
111 | /* | |
112 | * io scheduler registration | |
113 | */ | |
114 | extern int elv_register(struct elevator_type *); | |
115 | extern void elv_unregister(struct elevator_type *); | |
116 | ||
117 | /* | |
118 | * io scheduler sysfs switching | |
119 | */ | |
120 | extern ssize_t elv_iosched_show(request_queue_t *, char *); | |
121 | extern ssize_t elv_iosched_store(request_queue_t *, const char *, size_t); | |
122 | ||
123 | extern int elevator_init(request_queue_t *, char *); | |
124 | extern void elevator_exit(elevator_t *); | |
125 | extern int elv_rq_merge_ok(struct request *, struct bio *); | |
1da177e4 LT |
126 | |
127 | /* | |
128 | * Return values from elevator merger | |
129 | */ | |
130 | #define ELEVATOR_NO_MERGE 0 | |
131 | #define ELEVATOR_FRONT_MERGE 1 | |
132 | #define ELEVATOR_BACK_MERGE 2 | |
133 | ||
134 | /* | |
135 | * Insertion selection | |
136 | */ | |
137 | #define ELEVATOR_INSERT_FRONT 1 | |
138 | #define ELEVATOR_INSERT_BACK 2 | |
139 | #define ELEVATOR_INSERT_SORT 3 | |
797e7dbb | 140 | #define ELEVATOR_INSERT_REQUEUE 4 |
1da177e4 LT |
141 | |
142 | /* | |
143 | * return values from elevator_may_queue_fn | |
144 | */ | |
145 | enum { | |
146 | ELV_MQUEUE_MAY, | |
147 | ELV_MQUEUE_NO, | |
148 | ELV_MQUEUE_MUST, | |
149 | }; | |
150 | ||
1b47f531 JA |
151 | #define rq_end_sector(rq) ((rq)->sector + (rq)->nr_sectors) |
152 | ||
1da177e4 | 153 | #endif |